1. Field of the Invention
The present invention relates to an IC-incorporating card such as a PC card or a CF card.
2. Description of Related Art
Compact and portable information systems such as electronic personal organizers and digital cameras, for example, have a CF card slot in which a CF card (CompactFlash (trade mark)) is to be mounted. The CF card mounted in the CF card slot allows for extension of the capabilities of the portable information systems. The CF card is of a card shape as a whole and has, for example, a board mounted with an integrated circuit such as a memory IC, a connector mounted on the board for electrical connection to the CF card slot, a resin frame holding the board and the connector, and a pair of metal panels covering upper and lower sides of the board.
For static prevention, the metal panels are preferably grounded. This improves the reliability of the CF card. Japanese Unexamined Patent Publication No. 6-177573 (1994), for example, discloses a grounding structure which includes grounding terminals provided in the connector, and grounding spring elements respectively formed integrally with the grounding terminals as projecting toward the upper and lower metal panels to contact the metal panels for the grounding of the metal panels.
In the meanwhile, the CF card includes two types of CF cards in conformity with the CFA (CompactFlash Association) Standards, i.e., Type I having a thickness of 3.3 mm and Type II having a thickness of 5.0 mm. The CF cards of Type I and Type II have the same pin configuration, so that connectors to be used for these CF cards may have the same construction.
Where the aforesaid grounding structure is employed in which the grounding spring elements project from the connector to reach the upper and lower metal panels, however, the connector cannot be employed in common for the CF cards of Type I and Type II which have different thicknesses. Therefore, the connectors for the CF cards of Type I and Type II should separately be designed and manufactured, resulting in a cost increase.
Another conceivable grounding structure is such that spring members are provided between a ground pattern on the board and the upper and lower metal panels for the grounding of the metal panels. With this grounding structure, the CF cards of Type I and Type II can employ connectors of the same construction in common. However, the grounding structure requires an increased number of components, and reliable attachment of the spring members is not always easy, so that the grounding structure should manually be assembled. Further, the grounding reliability may be reduced due to displacement and dislodgement of the spring members, and the costs may be increased.
It is an object of the present invention to provide an IC-incorporating card having a grounding structure which ensures reliable grounding of metal panels thereof and employs a connector which is usable in common for cards having different thicknesses.
The IC-incorporating card according to the present invention comprises a board mounted with an integrated circuit, a resin frame defining an internal space for accommodating the board, first and second metal panels attached to the resin frame to define the internal space, a connector mounted on the board, and a grounding structure for grounding the first and second metal panels.
The connector has a plurality of contacts retained in a housing thereof for electrical connection to a card slot. The connector further has first and second grounding conductor elements connected to a ground contact of the plurality of contacts which is to be connected to a ground portion of the card slot, the first and second grounding conductor elements being exposed from the housing to be opposed to the first and second metal panels, respectively.
The grounding structure has a grounding connection element embedded in the resin frame, and the first and second metal panels are electrically connected to the ground contact with the first grounding conductor element being electrically connected to the first metal panel via the grounding connection element and with the second grounding conductor element being in direct contact with the second metal panel for electrical connection therebetween.
With this arrangement, the first metal panel is connected to the first grounding conductor element of the connector via the grounding connection element embedded in the resin frame, while the second metal panel is directly connected to the second grounding conductor element of the connector. This arrangement is applied to a relatively thick IC-incorporating card (e.g., CF card of Type II). Where the aforesaid connector is employed for a relatively thin IC-incorporating card (e.g., CF card of Type I), the first and second grounding conductor elements are respectively brought into direct contact with the pair of metal panels. Thus, the connector of the same construction is applicable in common to the plural types of IC-incorporating cards having different thicknesses, so that the production costs of the IC-incorporating cards can be reduced.
Since the grounding connection element connecting the first metal panel to the first grounding conductor element is embedded in the resin frame, the resin frame and the grounding connection element are handled virtually as a unitary member. Therefore, the card can easily be assembled with a reduced number of components. With the simplified construction, the assembling cost can be reduced. Further, the grounding connection element embedded in the resin frame can assuredly be connected to the first grounding conductor element of the connector with its position precisely defined, so that the first metal panel can assuredly be grounded.
The first and second grounding conductor elements may have substantially the same construction.
The grounding connection element is preferably integrated with the resin frame by simultaneous molding. With this arrangement, the grounding connection element integrated with the resin frame by the simultaneous molding can precisely be positioned, so that the electrical connection between the grounding connection element and the first grounding conductor element can reliably be established.
The grounding connection element is preferably formed integrally with the first metal panel. This arrangement ensures easy formation of the grounding connection element.
The grounding connection element is preferably a portion of the first metal panel bent at an edge thereof adjacent to the connector as extending through the resin frame toward the connector.
The foregoing and other objects, features and effects of the present invention will become more apparent from the following description of the preferred embodiments with reference to the attached drawings.